Poppet valve



C. PFANSTIEHL.

POPPET VALVE.

APPLICATION FILED JULY25, 1918.

2 22,822. Patent d. uly 25, 1922.

UNITED STATES PATENT. OFFICE.

CARL PFA NSTIEHL, OF HIGHLAND PARK, ILLINOIS, ASSIGNOR T0 PFANSTIEHLCOMPANY, INC., OF NORTH CHICAGO, ILLINOIS, A CORPORATION OF NEW YORK.

rorrn'r VALVE.

Application filed July 25,

To all whom it may concern:

Be it known that I, CARL PFANSTIEHL, a citizen of the United States,residing at Highland Park, in the county of Lake and State of Illinois,have invented a certain new and useful Improvement in Poppet Valves, ofwhich the following is a full, clear, concise, and exact description,refen ence being had to the accompanying drawings, forming a part ofthis specification.

This invention relates to poppet valves and is especially concerned withthe provision ofa poppet valve to be used as an exhaust valve forinternal combustion engines.

The object of this invention is to provide a poppet valve which may beused as an exhaust valve for internal combustion engines of such acharacterthat it will expand substantially the same amount underoperating conditions that the supporting portions of the engine expandunder the same conditions, so that it .will be unnecessary to provideany. loose connections in the operating mechanism of the poppet valve tocompensate for the difference in expansion between the valve and thesupporting portions of the engine, as it is necessary to do where thevalves are constructed of materials which expand different amounts underthe conditions under which internal combustion engines ordinarilyoperate.

In my Patent No. 1,283,287, dated October 29, 1918, I have described andclaimed a valve comprising a head of high speed steel and a stem ofnickel steel and have stated therein that the purpose of providing thestem of nickel steel is to compensate for the high co-efficient ofexpansion of the high speed steel head of the valve so that the changein length between the valve seat and the end of the valve stem for thetemperature at which the valve head and stem are operated will beexactly the-same as that of the cast iron portions of the engine. I havealso explained that the proportions of nickel in the alloy forming thestem must be varied for different lengths of valve stems and fordifferent facilities for carrying off the heat from the lower portionsof the stem.

Since filing the above application I have found that in order to providevalves in which the expansion is of substantially the same amount asthat of the supporting portions of the internal combustion engines forSpecification of Letters Patent.

1918. Serial No. 246,633.

a great many different types of engines it is necessary, 1n case theentire valve stem is made of' a n1ckel steel alloy, to provide acorresponding number of different steel alloys for the reason that it isnecessary to Patented July 25, 1922.

pose to construct valves of the type illustrated in the accompanyingdrawing in which the figure discloses a longitudinal section of myimproved valve structure.

In this figure the reference character 1 indicates the head of thevalve, which is preferably constructed of high speed steel. The. stem ofthe valve comprises two sections, 2 and 3 respectively. The section 2 isfused to the head 1 preferably by means of the process disclosed in myco-pending application Serial No. 138,780, and section 3 is welded ,orfused to section 2 in any desired manner.

I preferably form section 2 of the valve stem of ordinary low carbonsteel and section 3 of nickel steel having a higher percentage of nickelthan the stem of the valve disclosed in my Patent No. 1,283,287, abovereferred to. As stated in the last mentioned application an alloy havingany desired coefficient of expansion ranging from that of low carbonsteel to substantially nothing can be produced by alloying it withvarying percentages of nicke By making the percentage of nickel insection 3 of my improved valve sufliciently high I can'make any numberof valves for different types of engines having valves provided withvalve stems of different length and different facilities for carryingoff the heat and at the same time employ but one nickel steel alloy forconstructing valves for all these different types of engines. Thisresult is ac- (-omplishedv by changing the lengths of the sections 2 and3. For instance, if it is desired to produce a valve having acomparatively large expansion section 2 of low speed steel may be madecomparatively long and section 3 of the nickel alloy steel will be madecomparatively short, whereas if it is desired to provide a valve whichwill expand a lesser amount section 2 is made shorter and section 3longer. In this manner by varying the lengths of the sections 2 and 3 Iam able to produce valves having any desired degree of expansion andstill employ but two diiferent steels, whereas by constructing thevalves in accordance' w ith the method disclosed in my Patent No.1,283,287, referred to above, it is practically necessary to carry adifferent steel for manufacturing the valves of each different engine.

While I have described my improved-valve as comprising a head of highspeed steel it is to be --understood that my invention is not limited toavalve having a head formed of this material, and it is to be furtherunderstood that my invention is not limited to a valve in which the headis fused'or welded to the stem nor in which the different sections ofthe valve stems are made of the alloys referred to, but may be made ofdifierent alloys as long as they are correctly pro meagre portioned toproduce a valve having the desired degree of expansion.

Having thus described my invention, what I claim as new and desire tosecure by Letters Patent of the United States-is:

An exhaust valve for internal combustion engines including a stem havingtwo parts formed of metals having differing co-efl"1- c'ients ofexpansion theunion between the metals being so positioned between theends of the stem as to provide a total stem expansion which, underthetemperature at which the stem operates, substantially equals theexpansion of the valve housing under the temperature at whichitoperates, whereby the clearance between the end of the valve stem andits tappet Will not be materially altered through changes intemperature.

-In witness whereof, I hereunto subscribe my name this 18 day of July,A. D. 1918.

CARL P'FANSTIEHL.

WitneSses -J. SCHUMANN, C. W. BAOKE.

